What is the difference between overactive and underactive thyroid?

Hypothyroidism vs. Hyperthyroidism: What’s the Difference?

Were you recently diagnosed with hypothyroidism? If so, you’re likely aware your body’s thyroid gland is underactive. And you’re probably all too familiar with some of the associated symptoms like tiredness, constipation, and forgetfulness. These symptoms are frustrating. But with the right treatment plan, they can become manageable.


What is hypothyroidism? In short, your thyroid gland can’t make enough hormones to function well. The thyroid gland controls every aspect of your body’s metabolism. In hypothyroidism, the gland’s hormone production slows. This, in turn, slows your metabolism, which can lead to weight gain. Hypothyroidism is common, and affects about 4.6 percent of the U.S. population.

According to the American Thyroid Association, there’s no cure for hypothyroidism. However, there are medications that can treat the disease. The goal of the medication is to improve your body’s thyroid function, restore hormone levels, and allow you to live a normal life.

Hashimoto’s thyroiditis is the most common cause of hypothyroidism. With this condition, your body attacks its own immune system. Over time, this attack causes the thyroid to stop producing hormones as it should which leads to hypothyroidism. Like many autoimmune diseases, Hashimoto’s thyroiditis occurs more frequently in women than men.


As its name suggests, hyperthyroidism occurs when your body makes too much of the thyroid hormones, thyroxine (T4) and triiodothyronine (T3), and becomes overactive. If you have hyperthyroidism, you may experience a fast heartbeat, increased appetite, anxiety, sensitivity to heat, or sudden weight loss.

Hyperthyroidism most commonly occurs in three ways:

  • thyroiditis, or an inflammation of the thyroid
  • a thyroid nodule that produces too much T4 hormone
  • an autoimmune condition known as Graves’ disease

In hyperthyroidism, an irritation of your thyroid known as thyroiditis allows too much thyroid hormone to enter your blood. This can lead to pain and discomfort. Thyroiditis can also occur as the result of pregnancy. This is usually short-term.

Thyroid nodules are common in both hypothyroidism and hyperthyroidism. More often than not, these nodules are benign. In hyperthyroidism, these nodules can lead to an increase in your thyroid’s size or produce too much T4 thyroid hormone. Doctors don’t always know why this happens.

Graves’ disease causes the body to attack itself. This attack allows the thyroid gland to produce too much thyroid hormone. This autoimmune disease is often the underlying cause of hyperthyroidism. Graves’ disease causes your thyroid to make too much thyroid hormone.

Medications, radioactive iodine, or surgery are treatment options of hyperthyroidism. If left untreated, hyperthyroidism can cause bone loss or an irregular heartbeat. Both Hashimoto’s thyroiditis and Graves’ disease can run in families.

The Differences Between Hypothyroidism and Hyperthyroidism

Hypothyroidism causes symptoms like slowed metabolism, tiredness, and weight gain. Having an underactive thyroid can decrease or slow down your bodily functions.

With hyperthyroidism, you may find yourself with more energy, as opposed to less. You may experience weight loss as opposed to weight gain. And you may feel anxious as opposed to depressed.

The most common difference between the two diseases relates to hormone levels. Hypothyroidism leads to a decrease in hormones. Hyperthyroidism leads to an increase in hormone production.

In the United States, hypothyroidism is more common than hyperthyroidism. However, it’s not uncommon to have an overactive thyroid and then an underactive thyroid, or vice versa. Finding a skilled doctor who specializes in the thyroid, typically an endocrinologist, is an important part of your treatment plan.

The condition when the thyroid gland produces less amount of thyroid hormones is called hypothyroid, while the condition when there is the overproduction of hormones by the thyroid gland is called hyperthyroid. The thyroid gland is located in a front portion of the neck and affects almost whole body’s metabolic process.

The main function of thyroid gland is to store, secrete, and produce hormones especially triiodothyronine (T3) and thyroxine (T4) into the bloodstream that regulates numerous functions, including metabolism, body temperature, heart rate and blood pressure, growth and development of the brain and nervous system. It is seen that hypothyroidism is more common than hyperthyroidism.

Both the diseases are said to be as “autoimmune disease“. In this type there is direct cellular damage, and thus connective tissue (scar tissue) replace the cellular structure, this happens due to the attack of the antibodies or lymphocytes to the cell-membrane antigens, resulting in cellular lysis or an inflammatory response against the affected organ and gradually resulting in the decline of the function of the organ.

So precisely we can say that when body’s feel some frustrating symptoms like constipation, tiredness, forgetfulness, you should visit the doctor to confirm any imbalance in the level of hormones of the thyroid gland. And if the activity of these hormones is diagnosed to be abnormal, the result can be either hypothyroid or hyperthyroid.

When the production of hormones in the thyroid gland is underactive or is unable to make required amount for the proper function it is called hypothyroid. However, when there is an overproduction of the hormones, which is more than the required amount, it is called hyperthyroid.

Hereby we will consider the fundamental difference between both types, adding more information on them.

Content: Hypothyroid Vs Hyperthyroid

  1. Comparison Chart
  2. Definition
  3. Key Differences
  4. Conclusion

Comparison Chart

Basis for Comparison Hypothyroid Hyperthyroid
Meaning When the thyroid gland is unable to produce or secrete the required amount of thyroid hormones, leading to improper body’s function is called hypothyroid. When there is an overproduction of thyroid hormones by the thyroid glands and thus affecting the normal function of the body is called as hyperthyroid.
Also known as It is also called as the underactive thyroid. It is also known as the overactive thyroid.
Causes 1.Low-iodine diet.
2.Radiation exposure after cancer treatment
4.Hashimoto’s thyroiditis, or an autoimmune disorder or chronic lymphocytic thyroiditis.
5.Medications used in cancer treatment, psychiatric conditions and heart problems.
1.Swollen thyroid
2.Thyroid nodules
3.Graves disease (a disease that stimulates the thyroid hormones).
4. Tumours of the ovaries or testes.
5.Benign tumours of the thyroid or pituitary gland.
Symptoms 1.Slowed metabolism.
2.Weight gain.
4. Goiter (swelling of the thyroid gland).
5.Slow heart rate.
6.Sensitivity to cold.
7.Dry hair and hair loss.
9.Muscle cramps.
11.Carpal tunnel syndrome.
2.Feeling hot.
3.Itchy red skin.
4.Hair loss.
5.Running heart beat.
6.Weight loss.
7.Feeling worried or anxious.
8.Loss of consciousness.
9.Nausea and vomiting.
Effect on hormones It results in the decrease of hormones. It results in the increase of hormone production.
Diagnosis Test of thyroid-stimulating hormone (TSH), thyroid scan, thyroid-stimulating immunoglobulin (TSI) test, radioactive iodine uptake test. Test of thyroid-stimulating hormone (TSH), thyroid scan, thyroid-stimulating immunoglobulin (TSI) test, radioactive iodine uptake test, along with that T3 and T4 test.
Treatment Synthetic thyroid hormone (e.g., Levothyroxine) or corrective observed iodine supplementation. Beta blockers (e.g., Propanolol) to alleviate symptoms, anti-thyroid medications (e.g., Methimazole) to slow down over reactive thyroid.
Temperature Intolerance Cold Intolerance. Heat Intolerance.

Definition of Hypothyroid

The less production of thyroid hormone according to the body’s requirement is called hypothyroid, also termed as under production thyroid hormone. It is commonly known as Hashimoto’s thyroiditis. In this autoimmune disorder attacks the thyroid and resulting in the death of the tissue.

When thyroid glands are been removed due to hyperthyroidism disorder, the patient may catch hypothyroidism unless they follow the appropriate thyroid hormone replacement therapy.

A thyroid-stimulating hormone (TSH) has the normal range lying between .5 and 4.5 ml U/L. But if the level falls outside the provided range, the patient is said to have either hypothyroid or hyperthyroid.

The signs and symptoms include sleepiness, constipation, weight gain, cold intolerance, slow heart rate, tension, infertility, erectile dysfunction, depression, loss of memory, lack of concentration, swelling in eyelid, leg, hands, abdominal swelling, round puffy face, dry and pale skin, itchy skin, hair loss, prolonged and frequent periods, muscles stiffness, pains.

The treatment varies from person to person and the multiple causes of the occurrence of the disease, but generally, hypothyroidism is controlled by the use of a synthetic thyroid hormone or by giving proper iodine supplements. Sometimes condition like ‘myxedema coma‘ can also occur, it is a decreased level of consciousness, low body temperature, convulsions.

Definition of Hyperthyroid

The overproduction of thyroid hormones is called hyperthyroid also termed as an overactive thyroid. There can be many reasons for the overproduction of thyroid hormones, for example, post effect of Grave’s disease will result in overactive thyroid and thus formation of too much hormone in the body.

When there is a “flow” of an excess amount of hormones, leading to the inflammation of the glands is referred as subacute thyroiditis. Toxic diffuse goiter or Graves’ disease is the most common cause of hyperthyroidism overall. In this disease, thyroid gets swollen and sometimes even eyes. Due to the over activeness of the thyroid gland, it releases an excess amount of thyroid hormone into the blood stream.

The signs and symptoms include weight loss, diarrhea, hyperactive, heat intolerance, fast heart rate, infertility, erectile dysfunction, spontaneous abortion, nervousness, irritation, anxious, ankle swelling, pigmentation, itchy skin, hair loss, redness of the palms, infrequent periods, muscles weakness.

The diagnosis is same as discussed above, but along with the checking of the TSH level, the suspected patients are also asked to go for checking their T3 and T4 levels. Here the level of T3 and T4 gets higher than the normal. The other tests are the thyroid scan and the radioactive iodine uptake test.

In elderly patients, serious complications like ‘Thyrotoxicosis crisis (thyroid storm)‘ may occur, which results in increased heart rate (tachycardia ) which is also irregular and other signs of failure.

Key Differences Between Hypothyroid and Hyperthyroid

Following are the key differences between hypothyroid and hyperthyroid:

  1. When the thyroid gland is unable to produce or secrete the required amount of thyroid hormones, leading to improper body’s function is called hypothyroid; whereas when there is an overproduction of thyroid hormones by the thyroid glands and thus affecting the normal function of the body is called as hyperthyroid.
  2. Hypothyroid is also called as underactive thyroid while Hyperthyroid is also known as an overactive thyroid.
  3. Important causes of hypothyroid are low-iodine diet, radiation exposure after cancer treatment, Genetics, Hashimoto’s thyroiditis, or an autoimmune disorder or chronic lymphocytic thyroiditis, Medications used in cancer treatment, psychiatric conditions, and heart problems; while causes in hyperthyroid includes Swollen thyroid, Thyroid nodules, Graves disease ( a disease that stimulates the thyroid hormones), Tumors of the ovaries or testes, Benign tumors of the thyroid or pituitary gland.
  4. There are many signs and symptoms of hypothyroid like slowed metabolism, weight gain, tiredness, goiter (swelling of the thyroid gland), slow heart rate, sensitivity to cold, dry hair and hair loss, depression, muscle cramps, constipation, carpal tunnel syndrome. But signs and symptoms of hyperthyroid are opposite to that of hypothyroid which includes shakiness, feeling hot, itchy red skin, hair loss, running heartbeat, weight loss, feeling worried or anxious, loss of consciousness, nausea, and vomiting.
  5. Hypothyroid results in the decrease of the number of required hormones; Hyperthyroid results in an increase in the number of hormone production.
  6. Diagnosis of hypothyroid and hyperthyroid are same like the test of thyroid-stimulating hormone (TSH), thyroid scan, thyroid-stimulating immunoglobulin (TSI) test, radioactive iodine uptake test, but in hyperthyroid T3 and T4 test are also been done.
  7. Treatment of hypothyroid includes synthetic thyroid hormone (e.g., Levothyroxine) or correctively observed iodine supplementation, while Hyperthyroid treatment includes beta blockers (e.g., Propanolol) to alleviate symptoms, antithyroid medications (e.g., Methimazole) to slow down the over reactive thyroid.
  8. The person suffering from the hypothyroidism has intolerance with cold, while the person with hyperthyroidism has intolerance with heat.


Hence we conclude that both the disease are related to the imbalance in the regulation of the thyroid gland which secretes thyroid hormones. Hypothyroid is the condition also known as underactive thyroid, which results in the less production of the of the thyroid hormone, even less than the required amount, while hyperthyroid, which is also known as overactive thyroid is the condition when the thyroid gland overproduces the thyroid hormones.

Columbia Thyroid Center

Hypothyroidism and hyperthyroidism are two of the most common thyroid disorders, and though their names sound almost identical, the disorders themselves are very different. The easiest way to remember the difference is to recall that “hyper” means too much, like when they say someone is hyperactive, it means they have too much energy.

The thyroid is a butterfly shaped gland located in your neck just below the Adam’s apple. It’s part of the endocrine system and its primary function is to secrete a hormone that regulates your body’s growth and metabolism.

Hypothyroidism is when your thyroid isn’t producing enough hormones. Symptoms vary from person to person, but often include fatigue, increased sensitivity to cold, constipation, unexplained weight gain and a “puffy” face. If left untreated, hypothyroidism can cause obesity, joint pain, infertility and heart disease. It’s important to note that while these symptoms may be related to hypothyroidism, they may also be caused by other problems. The best way to make a diagnosis of hypothyroidism is to have a simple blood test. Fortunately, treatment of hypothyroidism with synthetic thyroid hormone is usually simple, safe and effective.

Hyperthyroidism, conversely, is when your thyroid is over-producing hormones. Symptoms often include sudden weight loss despite a strong appetite, rapid or irregular heartbeat, increased appetite, and nervousness, just to name a few. You might notice that these symptoms are very similar to the symptoms of a number of other health problems, and indeed, hyperthyroidism can be difficult to diagnose at first. However, once properly diagnosed, most people respond well to hyperthyroidism treatments, which can include anti-thyroid medication, surgery, or small amounts of radioactive iodine.

Hopefully this helps clear up any confusion you had about these two common thyroid disorders. For more information on the thyroid and its disorders, visit columbiathyroidcenter.org

What’s the Difference Between Hypothyroidism and Hyperthyroidism?

Your metabolism goes into overdrive when you have hyperthyroidism and slows way down with hypothyroidism. iStock (2)

The thyroid, a butterfly-shaped gland located in the front and at the base of your neck, acts as the control center for your body. (1) Hormones secreted by the thyroid help maintain the brain, heart, muscles, and other organs, and help the body to use energy properly. (1)

So when something goes awry that leads to overactive thyroid or underactive thyroid, your metabolism either revs up too high or slows way down, respectively. These two conditions — hyperthyroidism and hypothyroidism — affect the thyroid in different ways and therefore have distinct symptoms.

“The major difference between hypothyroidism and hyperthyroidism is the thyroid’s hormone output,” says Minisha A. Sood, MD, an endocrinologist at Lenox Hill Hospital in New York City. (2)

In simple terms, with hypothyroidism, or underactive thyroid, the thyroid gland doesn’t make enough thyroid hormone for the body’s needs. With hyperthyroidism, or overactive thyroid, the thyroid makes too much, explains Dr. Sood. (2)

The most common cause of hypothyroidism is an autoimmune disease called Hashimoto’s disease, a condition where the immune system makes antibodies that destroy thyroid cells and stop them from making the thyroid hormone.

The most common form of hyperthyroidism is a condition called Graves’ disease.

Some people with Graves’ disease have swelling in the front of their neck from an enlarged thyroid gland, called a goiter, as well as eyes that appear enlarged because of inflammation.

Symptoms of Hypothyroidism Versus Hyperthyroidism

With hypothyroidism, “your whole metabolism slows down — the heart rate is slower than normal, the intestinal tract becomes sluggish, and there is less heat production,” says Mario Skugor, MD, an endocrinologist at the Cleveland Clinic who specializes in thyroid disorders. (3)

As a result of an underactive thyroid you may experience:

  • Fatigue
  • Forgetfulness
  • Dry skin
  • Dry hair
  • Brittle nails
  • Constipation
  • Weight gain
  • Muscle cramps
  • Depression
  • Decreased menstrual flow
  • Swelling in the front of the neck (goiter)

“The weight gain that often accompanies hypothyroidism is a funny thing,” Dr. Skugor notes. “If a person with underactive thyroid can force him- or herself to maintain a normal activity level, he or she may only gain a few pounds,” he says. “But some people with hypothyroidism feel so tired they stop exercising, sleep more, and change their routine, which causes more weight gain.” (3)

In contrast, with an overactive thyroid, all body functions tend to speed up. Think of it as a racing car engine. “People with hyperthyroidism will have symptoms of a fast metabolism,” Skugor says. (3)

As a result of an overactive thyroid you may experience:

  • Feeling hot
  • Sweating
  • Problems falling asleep
  • Racing thoughts
  • Difficulty focusing on one task
  • Forgetfulness
  • Change in bowel habits, where bowels are looser
  • Elevated heart rate and palpitations
  • Anxiety, nervousness, or irritability
  • Weight loss
  • Menstrual problems
  • Fatigue

“It’s important to note that weight loss associated with overactive thyroid is not happy weight loss,” Skugor explains. “It is associated with muscle weakness and constant fatigue, so it isn’t something you want.” (3)

If you experience any of the above symptoms of thyroid disorders — either underactive thyroid or overactive thyroid — see your healthcare professional. They can order tests to determine whether your thyroid hormone levels are in the normal range, and if they are not, can provide treatments to ease your symptoms.

It’s also important to consider the other major differences between hypo- and hyperthyroidism. These include difference in risk factors, diagnosis, and overall outlook.

Incidence and Risk Factors: Who Is Affected by Thyroid Disorders?

Hypothyroidism is much more common, with about 1 in 20 people in the United States diagnosed with the disease after the age of 12. Hyperthyroidism is a little easier to diagnose, but is less common, with an incidence rate of 1 in 100. (1)

Women are more likely to get thyroid disease, and both hypothyroidism and hyperthyroidism occur more often in women over 60. About 1 in 8 women are estimated to have thyroid disease at some point during their lifetimes. (4) These thyroid disorders also tend to run in families. (1)

Thyroid problems can occur as a result of cancer treatments. You may also develop nodules directly on the thyroid gland, but these usually aren’t cancerous and don’t necessarily cause any issues with thyroid function. A biopsy and ultrasound may be needed to rule out thyroid cancer, though this type of disease is rare. (1)

Sometimes pregnancy can cause thyroid levels to fluctuate. Hypothyroidism is more common. Thyroid levels may not normalize for about a year after delivery. (1) Hypothyroidism is also a risk factor for women after menopause. (4)

Diagnosing Hypothyroidism and Hyperthyroidism

The first step in both hypo- and hyperthyroidism diagnoses is a simple blood test. Your doctor will likely ask you to fast for the test for the most accurate result. This means you can’t eat any food after midnight.

A blood test will measure three types of hormones. The first is called the thyroid-stimulating hormone (TSH), which is released by the pituitary gland in the brain. A high TSH result, in this instance, means your pituitary gland is in overdrive, likely trying to compensate for an underactive thyroid gland. (The pituitary gland can kick into overdrive because of other factors, though, independent of the thyroid gland). A low result means you’re getting an abnormal amount of thyroid hormones in the blood and may indicate hyperthyroidism. (5)

The two other hormones your doctor may check include free-thyroxine (T4) and total triiodothyronine (T3). Your doctor may also check Free-T4 levels, which is the measurement of T4 before it’s stored in various tissues throughout the body. Low levels of any of these hormones indicate hypothyroidism, while high levels point to hyperthyroidism. (5)

Subsequent diagnostic tests depend on what your doctor finds in your initial bloodwork as well as during a physical check of your thyroid. An enlarged thyroid gland may require an ultrasound to diagnose possible cysts. A fine needle biopsy is sometimes used in conjunction with an ultrasound. This involves taking a small sample out of the cyst to screen it for cancer. (4)

Another method used to diagnose hyperthyroidism is called a radioactive iodine uptake test. This is used in conjunction with an ultrasound. First, the technician will have you take a capsule containing radioiodine. A healthy thyroid gland takes up only the amount of iodine it needs. If images show that your thyroid takes up too much of the iodine, then you may have hyperthyroidism. The opposite is true of hypothyroidism. (4,5)

Treatment Differences Between Hypothyroidism and Hyperthyroidism

Treatment for hypothyroidism and hyperthyroidism differs. While the key to hypothyroidism treatment is to get your thyroid levels up, hyperthyroid treatment focuses on lowering hormone levels. (1) This can be a hit-and-miss process at first until your doctor figures out the right amounts of medicine you need for your thyroid to stabilize.

With hypothyroidism, lifelong use of medication is often required. (4) Levothyroxine (brand name Synthroid) is standard in hypothyroid treatment. It helps replace missing thyroxine (T4) hormones in the body. While you may need occasional dosage adjustments, most people don’t outgrow taking this medication.

Hyperthyroid treatment, on the other hand, may be temporary. Antithyroid medications work by stopping the thyroid gland from making too many hormones. These don’t damage the thyroid whatsoever. Sometimes beta-blockers are also used to minimize the effects of too much thyroid hormone on the body, such as heart palpitations. (4)

More severe cases of hyperthyroidism may require radioiodine treatments. Radioactive iodine destroys thyroid cells to decrease the release of hormones in the body. This approach is used when medications have failed. It often results in hypothyroidism, for which you’ll then need to take thyroid hormone medications. (4)

For people who want an alternative to radioiodine treatment or antithyroid medications, surgery is an option for hyperthyroidism. Surgery removes the part of the thyroid gland that is causing the underlying issues. Full surgical removal is called a thyroidectomy. A partial thyroidectomy means only one side of the thyroid gland is removed. If your entire thyroid is removed, your body no longer makes any thyroid hormone and you’ll need to take Levothyroxine. (4,6)

Complications, Prognosis, and Outlook for Thyroid Conditions

The overall outlook and prognosis varies between hypothyroidism and hyperthyroidism. With hypothyroidism, your levels and overall symptoms may improve with medication, but it’s a condition you’ll likely be treating for the rest of your life.

This is not necessarily the case with hyperthyroidism. If antithyroid medications work, then your thyroid hormone levels will normalize without any further issues.

Once you have any form of thyroid disease though, your doctor will monitor your condition with occasional blood tests to make sure your thyroid hormones are at optimal levels.

Complications of thyroid disease may include: (7,8)

  • Anxiety (seen more in hyperthyroidism)
  • Depression (seen more in hypothyroidism)
  • Weight fluctuations
  • Fertility issues
  • Birth defects
  • Heart problems
  • High blood pressure (seen in hyperthyroidism)

Thyroid 101: Hypothyroidism and Hyperthyroidism

There’s a small, butterfly shaped gland in your lower neck, the thyroid, that secretes hormones (T3 and T4) and affects almost every organ in the body, regulating metabolic processes and controlling body temperature.

When the thyroid doesn’t produce a normal hormone level, either not enough or too much, thyroid disease occurs. And according to Michigan Medicine endocrinologist Maria Papaleontiou, M.D. it’s actually more common than heart disease or diabetes.

An estimated 20 million Americans have some form of thyroid disease, but up to 60% of those that have it are unaware of the condition, according to the American Thyroid Association, with autoimmune diseases like Hashimoto’s disease and Graves’ disease among the most common culprits of hypothyroidism and hyperthyroidism, respectively.

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If the thyroid hormone levels are too low, referred to as hypothyroidism or underactive thyroid, the brain’s pituitary gland will produce more thyroid stimulating hormone (TSH). TSH prompts the thyroid to make more thyroid hormones in response to low levels.

If the thyroid hormone levels are too high, referred to as hyperthyroidism or overactive thyroid, the pituitary will produce less TSH in an attempt to decrease production of active thyroid hormone. The pituitary and thyroid glands work together in an effort to create an internal balance.

Risk factors

Thyroid disease can be up to eight times more likely in women than men, according to Papaleontiou. The reason for this sex difference remains unclear, but it may be in part because autoimmune diseases are more common in women and Hashimoto’s disease is the most common cause of hypothyroidism in the United States.

Besides history of an autoimmune disease, Papaleontiou says you’re also at greater risk of developing thyroid disease if:

  • You have a family history of thyroid disease.

  • You’re older than 60 years old.

  • You’ve received radiation treatment to the head, neck or chest.

  • You’ve been pregnant in the past 6 months.

  • You have an iodine deficiency.

  • You eat large amounts of food that contain iodine like kelp, or take medications containing iodine.

Symptoms of thyroid disease

When thyroid levels are too low, cells don’t get enough of the thyroid hormones and the body’s processes start to slow down. Symptoms of hypothyroidism aren’t always apparent but may include:

  • Cold intolerance

  • Fatigue

  • Dry skin

  • Forgetfulness

  • Constipation

  • Depressive mood swings

In contrast, hyperthyroidism causes the body’s processes to speed up and functions quicken, leading to symptoms like:

  • Nervousness or anxiety

  • Irritability

  • Increased sweating

  • Increased heart rate or hand tremors

  • Difficulty sleeping

  • Skin thinning

  • Frequent bowel movements

  • Fine, brittle hair

  • Muscle weakness

  • Weight loss

  • Lighter, less frequent menstrual periods

  • Lack of energy and fatigue

“The symptoms can be variable and non-specific, so the only way to definitively diagnose a thyroid condition is with a simple blood test,” says Papaleontiou, a member of the University of Michigan Institute for Healthcare Policy & Innovation.


Fluctuating thyroid function can be defined as a spontaneous shift of functional thyroid state from hyperthyroidism to hypothyroidism orvice versa. In autoimmune thyroid disease, thyroid function can fluctuate. Thyroid-stimulating immunoglobulin (measured by the capacity of serum immunoglobulin to stimulate cAMP production in cultured human thyroid cells) stimulates the thyroid gland while blocking antibodies (measured by the degree of inhibition of TSH-stimulated cAMP production of cultured human thyroid cells by serum immunoglobulin) do the opposite. At a particular point, it is the balance between the two antibodies that decides the functional thyroid state. Although not common, similar cases have been reported for hyperthyroidism to hypothyroidism1 andvice versa.2 3 The end point of all reported cases was hypothyroidism, either spontaneously or as a result of treatment, but our patient remained in a euthyroid state without intervention.

Thyrotoxicosis factitia should be considered in the differential diagnosis. Clinically, the presence of goitre, ophthalmopathy or dermopathy is against the diagnosis. In thyrotoxicosis factitia, radioactive iodine uptake of the thyroid gland will be negligible, and serum thyroglobulin and antithyroid antibodies will be undetectable. Also, on biochemical testing, serum T3 is likely to be normal or low with high serum thyroxine and suppressed TSH. The presence of goitre, high serum T3 and high titre of antibodies clearly argue against such a diagnosis in our patient.

The next question is whether or not we can predict such fluctuating behaviour of the thyroid gland. No clear answer is available. Progressive destruction of the thyroid gland or production of TSH receptor blocking antibodies may be responsible for the development of a hypothyroid state in patients with Graves’ hyperthyroidism.4 One can assume that blocking antibody plays a greater role than structural damage of the gland in such cases, otherwise the chance of development of a hyperthyroid phase would be very low. On the other hand, hypothyroid patients with radioiodine uptake are likely to remit,5 in contrast to those with normal or low uptake. Finally, there may be some yet unidentified factors other than stimulating and blocking antibodies, which are responsible for such fluctuations. It is interesting to note that the very high level of serum TSH at diagnosis and follow-up did not predict the outcome in our patient. Thus, a very high TSH or a very low FT4 does not necessarily mean the patient will have permanent hypothyroidism.

We believe that radioactive iodine is the best way to treat the hyperthyroid phase, with subsequent observation. Our patient’s hyperthyroid phase was short lasting and of less magnitude but such a treatment option will be considered in future, if necessary. In the hypothyroid stage, the only option remains replacement with thyroxine to keep the patient euthyroid. Surgery is an alternative option in the hyperthyroid patient after stabilisation with a blocking–replacement regimen.

Thyroid and Parathyroid Disorders – Otolaryngology

Depending on the specific problem, we may conduct an ultrasound of the neck to identify abnormalities. Ultrasounds also allow us to guide a needle biopsy, if necessary, to evaluate nodules or lymph nodes in the neck. Other imaging tests that may be ordered include CAT scan, MRI, and nuclear medicine tests such as radioiodine scans and PET scans.

Treatment for Thyroid and Parathyroid Disorders

At the University of Michigan, each patient is carefully evaluated by our team of experts so the best decision can be made on the most appropriate course of treatment. Deciding which treatment is best for each patient depends on the cause and severity of the disease, as well as a number of other factors.

We see patients with a wide range of thyroid disorders, including:

  • Thyroid nodules are growths or lumps in the thyroid gland. They are fairly common and can be found in a normal size or enlarged thyroid gland. Around 95% of nodules are benign, or non-cancerous, in which case no specific treatment is needed, and the thyroid can simply be followed to make sure the nodules don’t become a problem over time. If your physician is concerned that your nodule may be cancerous or is large enough to cause problems with breathing or swallowing, surgery may be recommended.
  • Hyperthyroidism is a disorder caused by an overactive thyroid that causes the body to speed up. It can cause weight loss, a faster heartbeat, sweating, or feelings of nervousness. Graves’ Disease is one of the main causes of hyperthyroidism. It is an autoimmune disease, more common in women than men, and can be associated with a special type of eye abnormality (Graves’ eye disease). If untreated, hyperthyroidism can lead to serious heart, bone and other problems. The most common treatments for hyperthyroidism are anti-thyroid medicine and radioactive iodine.
  • Hypothyroidism is a disorder caused by an under-active thyroid that may lead to changes in the hair or skin, fatigue and weakness, memory problems, or other issues. Hashimoto’s Thyroiditis, also known as Hashimoto’s disease, is an autoimmune disease that causes the body’s immune system to produce antibodies that attack thyroid tissue and damage the gland, leading to an under-productive thyroid. Hypothyroidism can usually be easily treated with thyroid hormone medicine, typically levothyroxine, which is identical to the main thyroid hormone made by the thyroid gland.

We treat the following parathyroid disorders:

  • Hypoparathyroidism occurs when the body does not produce enough PTH hormone and calcium levels fall below normal. Hypoparathyroidism is usually treated with a special form of vitamin D (calcitriol) and with calcium tablets. Careful monitoring is required to optimize the dosages.
  • Hyperparathyroidism occurs when the body continues producing PTH hormones even though calcium levels are higher than normal. For primary and tertiary hyperparathyroidism, surgery is the preferred method of treatment. Surgically removing the enlarged or overactive parathyroid can permanently cure the parathyroid disorder, with minimally invasive techniques available for certain patients.
  • Primary Hyperparathyroidism is an increase in calcium levels in the blood caused by the growth of benign, or non-cancerous, tumors on one or more of the parathyroid glands. It causes both the calcium and PTH levels to be above normal.
  • Secondary Hyperparathyroidism is a change in parathyroid function due to Vitamin D deficiency or renal (kidney) failure. Vitamin D deficiency is easily treated with medication and does not require surgery. Secondary hyperparathyroidism due to renal failure can be controlled with medication in some instances but for those patients with extremely high parathyroid hormone levels surgery may be needed to adequately control the condition.
  • Tertiary Hyperparathyroidism is seen in patients who have undergone kidney transplants and have abnormally high parathyroid hormone and calcium levels.


Hypoparathyroidism is the combination of symptoms due to inadequate parathyroid hormone production. This is a very rare condition, and most commonly occurs because of damage to or removal of parathyroid glands at the time of parathyroid or thyroid surgery.

Hypoparathyroidism is the state of decreased secretion or activity of parathyroid hormone (PTH). This leads to decreased blood levels of calcium (hypocalcemia) and increased levels of blood phosphorus (hyperphosphatemia).

Hypoparathyroidism Symptoms

Symptoms can range from quite mild (tingling in the hands, fingers, and around the mouth) to more severe forms of muscle cramps. The most severe symptoms are tetany (severe muscle cramping of the entire body) and convulsions (this is very rare).

Parathyroid gland insufficiency is quite rare, but it can occur in several well-defined ways. The most common cause of hypoparathyroidism is the loss of active parathyroid tissue following thyroid or parathyroid surgery. Even more rare is a defect present at birth (congenital), where a person is born without parathyroid glands. Occasionally, the specific cause of hypoparathyroidism cannot be determined.

Two Types of Hypoparathyroidism

  • Deficient parathyroid hormone secretion
  • Inability of the kidneys and bones to respond to PTH

Deficient Parathyroid Hormone Secretion

This type of hypoparathyroidism is the easiest to understand. A patient afflicted with this condition simply has too little (or a complete absence of) parathyroid tissue; therefore, inadequate PTH is produced.

There are 2 major causes of this problem:

Cause #1: Hypoparathyroidism Following Thyroid or Parathyroid Surgery

The first (and by far most common) cause of inadequate parathyroid hormone production is the accidental removal of parathyroid glands during thyroid surgery. Although the vast majority of thyroid operations are not associated with hypoparathyroidism, this complication can occur in about 1% to 3% of cases following a total thyroidectomy (the removal of the entire thyroid).1

Because of the close relationship that the thyroid and parathyroid have to one another (including sharing the same blood supply), the parathyroid glands can be injured or removed accidentally when the much larger thyroid is removed. This is a well known but uncommon complication of thyroid surgery and is one of the primary dangers of thyroid surgery.

A number of research studies have shown that surgeons with little experience in thyroid surgery are much more likely to accidentally remove the parathyroid glands2,3. These studies have shown that surgeons performing more than 100 thyroid operations per year are much less likely to have these complications. This is why most endocrinologists will explain to their patients that they should find the most experienced thyroid surgeon available.

Many patients who have a very successful thyroid operation can have a transient inadequate secretion of PTH for several days following surgery on the thyroid, so the diagnosis of post-surgical hypoparathyroidism cannot be made immediately following surgery. It is common for surgeons to give their thyroid patients calcium pills for a few days after surgery to prevent any symptoms from the transient lack of PTH.

The second operation associated with post-operative hypoparathyroidism is parathyroid surgery, or “parathyroidectomy.” Parathyroid surgery is performed for patients with overactive parathyroid glands causing a disease called hyperparathyroidism.

Since hyperparathyroidism is typically caused by one or more parathyroid tumors, surgery for hyperparathyroidism is aimed at removing the parathyroid tumor(s) and leaving behind the normal parathyroid glands. We all have 4 parathyroid glands, but we can live just fine (and not have hypoparathyroidism) if we have half of one parathyroid gland that is functioning normally.

The goal of parathyroid surgery is to remove those parathyroid glands that are overproducing PTH. But occasionally, too much parathyroid tissue is removed during the operation. Like thyroid surgery, the incidence of this complication is related to the experience of the surgeon and is why endocrinologists typically recommend surgeons with the most experience. Surgeons with little experience can have as many as 5% of their patients develop permanent hypoparathyroidism, while surgeons performing more than 100 parathyroid operations per year typically have hypoparathyroidism complications very rarely.4,5,6

Cause #2: Idiopathic HypoparathyroidsimDeficient parathyroid hormone (PTH) secretion without a defined cause is termed idiopathic hypoparathyroidism. This disease is rare and can be congenital or acquired later in life.

  • Congenital Hypoparathyroidism: Patients in this category are born without parathyroid tissues. Most patients with congenital hypoparathyroidism have no family history of the disease. Those who do may have any one of a number of congenital causes.

    The inherited forms tend to arise from abnormal genes that may:

    1. encode abnormal forms of PTH or its receptor
    2. prevent normal conduction of cell signals from the PTH receptor to the nucleus
    3. prevent normal gland development before birth.

    Hypoparathyroidism with onset during the first few months of life can be permanent or temporary. The cause is usually unknown if spontaneous resolution occurs. If it does not, it will usually manifest by 24 months of age.

    Finally, if a woman with overactive parathyroid glands and high calcium levels (hyperparathyroidism) becomes pregnant, the excess calcium can enter the fetus and suppress the baby’s parathyroid gland development. These babies are at risk of being born with under-developed parathyroid glands. This is why it recommended that pregnant females with high blood calcium levels have their parathyroid operation before the middle of the second trimester of pregnancy, to decrease the chance of the child being born with poorly formed parathyroid glands.7 Usually this will not result in permanent parathyroid gland dysfunction in the child.

  • Acquired Hypoparathyroidism: The acquired form of this disease typically arises because the immune system has developed antibodies against parathyroid tissues in an attempt to reject what it sees as a foreign tissue. This disease can affect the parathyroid glands in isolation or can be part of a syndrome that involves many organs.
    An antibody that binds to the calcium sensor in the parathyroid gland has been discovered in the blood of patients with autoimmune hypoparathyroidism. It has been proposed that such binding “tricks” the parathyroid gland into believing that the blood level of ionized calcium is high. Responding to this signal, the parathyroid stops making PTH.

Hypomagnesemia: Can Cause Low Calcium Levels

The element magnesium is closely related to calcium in the body. When magnesium levels are too low, calcium levels may also fall. Once low magnesium levels are recognized it is usually very easy to fix. Chronic alcoholism is a frequent cause of low magnesium levels.

Resistance to Parathyroid Hormone (Pseudo-hypoparathyroidism)

This disease is extremely rare. Like hypoparathyroidism, this disease is characterized by hypocalcemia (too low calcium levels) and hyperphosphatemia (too high phosphorus levels), but patients with pseudo-hypoparathyroidism (or resistance to PTH) are distinguished by the fact that they produce PTH, but their bones and kidneys do not respond to it. Even if PTH is given to them in their veins, they do not respond to it. Therefore, these rare individuals have plenty of PTH, but their organs do not behave appropriately to it. They appear to have hypoparathyroidism, but they do not—thus the name pseudo-hypoparathyroid.

Treatment of Hypoparathyroidism

Vitamin D and calcium supplements are the primary treatments for hypoparathyroidism, regardless of the cause. The majority of patients need to take calcium several times per day along with high-dose vitamin D once per day.

Updated on: 03/12/18 Continue Reading Osteoporosis and Parathyroid Disease View Sources

Thyroid and Parathyroid Disorders

Thyroid Disorders

The thyroid gland, located at the base of the neck, produces hormones that regulate metabolism, heart rate and body temperature. Every cell in the body depends on the thyroid hormones. The thyroid gland is prone to several disorders:

Hyperthyroidism, or overactive thyroid, occurs when the thyroid makes too much thyroid hormone. The most common cause of hyperthyroidism is Graves Disease, an autoimmune disease that makes the thyroid make excess hormone. Other causes include thyroid nodules, inflammation of the thyroid, consuming too much iodine and too much synthetic thyroid hormone, which is used to treat underactive thyroid. Symptoms include:

  • Being nervous or irritable
  • Mood swings
  • Fatigue or muscle weakness
  • Heat intolerance
  • Trouble sleeping
  • Hand tremors
  • Rapid and irregular heartbeat
  • Frequent bowel movements or diarrhea
  • Weight loss
  • Goiter, which is an enlarged thyroid that may cause the neck to look swollen

Once diagnosed, hyperthyroidism can be treated with antithyroid medicines, radioactive iodine to destroy the thyroid gland and/or surgical removal. If the thyroid is removed or destroyed, patients must take thyroid hormone replacement pills.

Hypothyroidism is defined as an underactive thyroid. Women are more commonly diagnosed with hypothyroidism, which can be caused by the autoimmune disorder Hashimoto’s disease, thyroid nodules, thyroiditis, congenital hypothyroidism, surgical removal or radiation treatment of the thyroid. Symptoms include:

  • Fatigue
  • Weight gain
  • A puffy face
  • Cold intolerance
  • Joint and muscle pain
  • Constipation
  • Dry skin
  • Dry, thinning hair
  • Decreased sweating
  • Heavy or irregular menstrual periods and fertility problems
  • Depression
  • Slowed heart rate

Hypothyroidism can be controlled with a daily dose of synthetic thyroid hormone.

Benign Goiter

Goiter is often caused by a diet deficient in iodine and is not common in the United States of America. When goiter does occur among Americans, a more common cause is an increase in thyroid stimulating hormone (TSH) that is a result of hypothyroidism. This condition may be medically managed by providing thyroid hormone in the form of a pill.

Patients may be referred for surgery if the goiter continues to grow, especially if it begins to compress on other structures in the neck such as the trachea and esophagus. Although the incidence for cancer is small, surgery would be recommended if it is suspected.

Thyroid nodules

Nodules, which can often be felt as a lump in the neck, may occur within the thyroid gland. More than 90 percent of all thyroid nodules are benign (non-cancerous) growths.

Risk factors for thyroid cancer include exposure to radiation (including previous treatment for head and neck cancers), personal or family history of goiter (enlarged thyroid) and certain inherited genetic syndromes. In addition to a lump in the neck, symptoms may include changes to the voice, difficulty swallowing and pain in the neck and throat. Patients may also have swollen lymph nodes in the neck.

Physicians diagnose thyroid cancer in a number of ways, including a physical exam, blood tests to measure levels of thyroid stimulating hormone, a fine needle biopsy to examine cells in the thyroid and imaging tests such as a thyroid ultrasound.

Some patients who have cancerous nodules can undergo is a minimally invasive, video-assisted thyroidectomy. In this procedure, surgeons use an endoscope to remove all or part of the thyroid. Some patients may also have radioactive iodine treatments (or internal radiotherapy) after their surgery.

Parathyroid Disorders

Parathyroid glands are four small glands in the neck that make a hormone that helps regulate the level of calcium in the body. Disorders of the parathyroid include:


Hyperparathyroidism is a common disease of the parathyroid gland caused by overactivity of one or more of the parathyroid glands. As a result, the glands make too much of the parathyroid hormone and can cause a serious calcium imbalance. Hyperparathyroidism can be caused by tumors that elevate the level of parathyroid hormone, which then causes a rise in the level of Ca2+ (calmodulin-dependent protein kinase) in the blood, at the expense of calcium stores in the bones. Over time, patients may develop osteopenia, in which the bones become brittle and there is an increased risk of fracture.

Treatment for hyperparathyroidism involves the removal of the abnormal gland or glands. In about 90 percent of cases, only one of the four glands has been affected by a benign tumor and that gland is the only one that is hypersecreting. This condition is called parathyroid adenoma.

In only about 10 percent or fewer cases, patients with hyperparathyroidism have had all four glands grow large (hyperplasia) and secrete too much parathyroid hormone (PTH). This condition is called parathyroid hyperplasia.

Parathyroid Tumors

A parathyroid adenoma is a noncancerous (benign) tumor found in the parathyroid glands, and can be caused by a genetic problem. The most common cause of parathyroid adenoma is hyperparathyroidism, which leads to increased blood calcium levels.

There is a rare cancer that sometimes forms in tissues of one or more parathyroid glands. That cancer can be treated with surgery and/or radiation therapy. Surgeons at GW Hospital offer minimally invasive parathyroidectomy, with and without video assistance. In the video-assisted surgery, physicians use targeted incisions and endoscopes to provide more precise localization of parathyroid tumors and remove the affected gland.

When patients have hyperplasia, in which all four glands are enlarged, all hypersecreting glands are typically removed surgically. Then, part of one gland is either re-implanted in a muscle in neck or forearm, or part of one gland is left in place if it is not enlarged.

Hypothyroidism vs. Hyperthyroidism

Hypothyroidism is a condition when there is a deficiency of thyroid hormone in the body. Hyperthyroidism is characterized by excessive amounts of thyroid hormone in the body. Both hypothyroidism and hyperthyroidism are extremely different cases.

The signs and symptoms of hyperthyroidism include increased heart rate ‘“ tachycardia, increased activity of bowel movements, difficulty in sleeping, intolerance to heat, nervousness and palpitation, increased respiratory rate, increased moisture of the skin, increased metabolic rate, soft and fine hair, wandering mind, sweating, scanty menstrual periods, infertility, muscle weakness, nervousness and soft nails.

In hypothyroidism, there are symptoms such as bradycardia- decreased heart rate, constipation, intolerance to cold, memory problems, coarse dry hair, slow speech movements, slow walking movements, dry skin, brittle nails, weight gain, fatigue, irritability, infertility, puffy face, loss of eyebrow hair, and heavy menstrual periods.

The causes of hypothyroidism include medications like lithium carbonate, genetic, decreased level of iodine in the body, disturbances in the pituitary gland and hypothalamus, and infections mainly viral and bacterial. Hashimoto’s thyroiditis is an immune disorder in which the thyroid gland is attacked and damaged.

Hyperthyroidism is caused by any growth present in the thyroid gland. Grave’s disease is an immunological disorder affecting the thyroid gland. The classical feature of it is exophthalmos ‘“ a protruding eye ball, which is absent in hypothyroidism. Hyperthyroidism can also lead to thyrotoxicosis.

The treatment for hypothyroidism includes thyroid hormones. It is given life long to the patient. Thyroxine is the supplement given to the patient. Thyroxine is T4 hormone of the thyroid gland. The patient is advised to take this medication early in the morning. The treatment for hyperthyroidism is anti-thyroid drugs which include propylthiouracil. It will decrease the production of thyroid hormones.

Before taking any medications for hypo or hyperthyroidism, the drug interactions should be considered. If there are high levels of thyroid stimulating antibodies in the blood of an infant, then the recommended treatment is exchange blood transfusion. This will decrease the antibody levels in the blood.

The diagnosis for hypothyroidism and hyperthyroidism includes the estimation of levels T3 and T4, the thyroid hormones and TSH level. In hypothyroidism, there is decrease in the thyroid hormones level ‘“ T3 and T4 and increase in the levels of TSH. In hyperthyroidism, there are increased levels of thyroid hormones T3 and T4 and decrease in the levels of TSH. TSH is thyroid stimulating hormone.

1. Hyperthyroidism is increased levels of thyroid hormones whereas hypothyroidism is decreased levels of thyroid hormones.
2. Hyperthyroidism can lead to thyrotoxicosis and grave’s disease whereas hypothyroidism does not produce those diseases.
3. There is faster metabolism in hyperthyroidism while there is a slow metabolism in hypothyroidism.
4. Hypothyroidism is treated by supplements of thyroid hormones and hyperthyroidism is treated by anti-thyroid drugs.
5. Hypothyroidism shows decreased levels of T3 and T4 and increased levels of TSH whereas in hyperthyroidism, there is an increased levels of T3 and T4 and a decreased level in TSH.

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